Note: Descriptions are shown in the official language in which they were submitted.
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ATTORNEY DOCKET NO: DBZ/444G
COMPUTER AIDED DESIGN INTERFACE
Field of the Invention
The present invention relates to computer automated design
(CAD) systems and software and hardware therefor.
Background of the Invention
Computer automated design (CAD) systems have matured over
the last several years, and now are used in nearly all design environments to
speed the design process and increase its accuracy, benefitting both consumers
and manufacturers. However, while these systems have been useful, their
interfaces continue to be refined and improved, and certain difficulties with
the
use of such systems remain to be overcome.
For example, computer automated design systems are often
used to design objects intended to be dimensionally matched to existing plans.
One example is CAD software used to design architectural features that mate
to an existing structure. One example of CAD software marketed for this
purpose is the "DesignFast" product licensed by the assignee hereof to its
customers, and intended for use in developing plans for concrete forms to be
used in creating concrete walls. Other examples include an application known
as Paschal Plan Light or PPL, marketed by Paschal Werk - G. Maier GmbH of
Steinach, Germany, a program known as "Tipos", available from the German
form manufacturer Doka has and discussed at the Doka web site,
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http://www.doka.com/TiposDoka/index_en.htm, and a product known as
"Elpos" and available from Peri, www.peri.de.
A difficulty with CAD systems, such as those identified above,
is that the designer often must develop a plan that uses existing structures
or is
compatible with existing structures. These existing structures may be
dimensioned in multiple incompatible units, such as English units (yards,
feet,
inches) and/or metric units (meters, centimeters, millimeters), and the
designer
must then perform unit conversions to create compatibly dimensioned plans in
the CAD system. Such unit conversions are difficult and introduce a likely
source of human error.
One known solution to this difficulty, is to use a calculator or
other special purpose device to perform unit conversions. For example, U.S.
Patent 4,860,233 shows a calculator designed to handle math operations on
mixed English and Metric unit quantities, and inch - fractional foot and
fractional inch - decimal inch conversions. Other patents in the general
subject matter area include No. 4,336,653 (English unit to metric unit
conversion device), No. 4,322,608 (Metric-English measurement comparator
device), No. 4,282,514 (Electronic converter), and 4,228,516 (Computer for
metric conversion).
Unfortunately, this known solution is not convenient for a
designer using CAD software, as it requires the designer to utilize a device
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separate from the CAD system to perform unit conversions, and then enter the
converted measurements into the CAD system, a process having a continuing
risk of human error.
Another difficulty with existing CAD systems relates to the
storage of designs and error recovery.
To protect from errors, many applications, including word
processors and graphical editors, provide for an undo function. Thus, if a
command is executed accidentally or incorrectly on content currently in
memory, the command can be undone, returning the subject content to its state
10, prior to execution of the command. In some applications, only the most
recent
command executed may be undone, whereas in others, all commands executed
since a file was opened, or the since the file was last saved, can be undone.
An
example of such an undo function is described in U.S. Patent 6,063,128,
referencing Fig. 2 at col 10, line 49 et seq.
Many applications also provide for automatic data backup.
Specifically, many applications will automatically save content currently in
memory, so that in the event of a power failure or computer failure, there
will
be a saved copy of the content which can be used as a starting point to
continue after the failure is corrected.
Unfortunately, these existing processes do not adequately
protect against errors, for several reasons. First, the undo function has the
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limitation that erroneous commands may not be undone if they are outside the
scope of the undo function, e.g., if the command is no longer on the
application's undo queue, or the command was executed during a previous
invocation of the application, after which the file was saved and the
application closed, destroying undo information. In such cases, the only
option available to a user is to manually undo a command, which can be
tedious and subject to human error. In addition, functions for automatically
saving content do not preserve all changes made, but only those changes made
until the time of the most recent automatic backup was saved. Changes after
the last automatic save are lost in the event of a failure. Furthermore,
automatically saved content is typically deleted when an application is
closed,
so changes may be inadvertently lost if the application is inadvertently
closed
without saving changes made.
A further difficulty with known CAD systems, such as Acad,
Micro station, Solid works, relates to the printing of content. Typically,
printing device settings are embedded by CAD software into files created by
the originating system. These settings are typically unique to a particular
brand and model of printer, and as a consequence, when a file is transmitted
from one user to another who has a different printing environment, often the
file must be modified before it can be printed. The required changes may vary,
including the plotter, file size, line/pen weight, B&W/Color/Grayscale
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settings, scale, and others. These settings may need to change for each page
in
a transferred file. In extreme cases, every page of a 99 page file will need
modification before printing on the other user's system.
Summary of the Invention
The present invention addresses the difficulties with CAD
systems discussed above, by its multiple aspects.
In one aspect, the invention features a computer aided design
system and program product in which dimensions for drawing tools may be
entered as an arithmetic combination of quantities expressed in both English
and metric units. The system converts the units of the input quantities, and
combines the converted quantities to produce a dimension in a common unit,
thus greatly streamlining the process of creating a drawing and reducing the
likelihood for human error.
In a second aspect, the invention features a computer aided
design system having an undo tool that stores undo in a file in nonvolatile
storage. The file contains a representation of each drawing tool invoked by
the
user, so that any and all drawing operations done on a file, may be undone
based upon data in nonvolatile storage, at any subsequent time, even after a
file has been saved and retrieved, or after a file has been transferred from
one
user to another.
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In a third aspect, the invention features a computer aided design
system and program product in which drawn content is associated with a paper
size and orientation, rather than a specific printer. The system associates
each
paper size and type with a printer, so that when printing a page, the paper
size
and type associated therewith can be used to select a printer. In this way,
content may be printed on an appropriate printer based upon a paper size and
orientation, without storing printer selections or details in the file. This
permits files to be printed by different users, having different printers,
without
requiring modification of the file.
The above and other objects and advantages of the present
invention shall be made apparent from the accompanying drawings and the
description thereof.
Brief Description of the Drawing
The accompanying drawings, which are incorporated in and
constitute a part of this specification, illustrate embodiments of the
invention
and, together with a general description of the invention given above, and the
detailed description of the embodiments given below, serve to explain the
principles of the invention.
Fig. 1 illustrates a computer aided design system in accordance
with principles of the present invention;
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Fig. 2 illustrates the screen displays on the CAD system of Fig.
1;
Fig. 3 illustrates a dimensional input window utilized by a
parser in accordance with principles of the present invention;
Fig. 4 is a flow chart of the operations of the parser of the CAD
system of Fig. 1;
Fig. 5 illustrates some of the data stored by the CAD system of
Fig. 1;
Fig. 6 is a flow chart of the operations of the user interface of
the CAD system of Fig. 1 when undoing and redoing drawing tool operations;
and
Fig. 7 is a flow chart of the operations of the user interface of
the CAD system of Fig. 1 when printing content.
Detailed Description of S12ecific Embodiments
Referring now to Fig. 1, a computer aided design (CAD)
system 10 in accordance with principles of the present invention comprises a
software application operating on the CPU 12 of a general purpose computer
such as a desktop computer system built around an Intel-compatible processor
and the Microsoft Windows operating system. The application on the
processor may be written in any number of source languages such as the C++
programming language.
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It will be appreciated that the methods described here are
computer implemented, but otherwise do not require any specific
computerized implementation. Those skilled in the art will appreciate that the
method and apparatus of the present invention apply equally to any computer
system, regardless of whether the computer system is a complicated multi-user
computing apparatus or a single user device such as a personal computer or
workstation. Thus, the computer system used for the CAD system 10 can
comprise IBM compatible personal computers running OS/2 or Microsoft's
Windows, Apple compatible personal computers using Motorola or PowerPC
processors, Linux or Unix compatible computers, or mainframe servers using
Unix or another mainframe operating system.
The CPU 12 of the system 10 suitably comprises a processor,
volatile memory such as DRAM, nonvolatile memory such as disk storage,
and a user interface such as a graphics card, keyboard and mouse controller,
all
of which are interconnected via one or more system bus. Note that various
modifications, additions, or deletions may be made to CAD system 10
illustrated in Fig. 1 within the scope of the present invention such as the
addition of cache memory or other peripheral devices. Fig. 1 is presented to
simply illustrate some of the salient features of an exemplary computer system
10.
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The processor of the CPU 12 performs computation and control
functions of CAD system 10. The processor may comprise a single integrated
circuit, such as a microprocessor, or may comprise any suitable number of
integrated circuit devices andJor circuit boards working in cooperation to
accomplish the functions of a processor. The processor suitably executes a
computer program within memory of the CPU 12.
The nonvolatile memory may be magnetic disks (e.g., hard
disks or floppy diskettes) or optical storage devices (e.g., CD-ROM). One
suitable storage device is a direct access storage device (DASD). In this
application, the term "disk" will be used to collectively refer to all types
of
storage devices, including disk drives, optical drives, tape drives, etc.
It is important to note that while the present invention has been
(and will continue to be) described in the context of a fully functional
computer system, those skilled in the art will appreciate that the mechanisms
of the present invention are capable of being distributed as a program product
in a variety of forms, and that the present invention applies equally
regardless
of the particular type of signal bearing media to actually carry out the
distribution. Examples of signal bearing media include: recordable type media
such as floppy disks (e.g., a floppy disk) and CD ROMS, and transmission
type media such as digital and analog conununication links, including wireless
communication links.
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Referring now to Fig. 2, details of the user interface of a CAD
system can be elaborated. The screen display includes a workspace 20 on
which a drawing 21 is generated. As seen best in Fig. 2, the workspace resides
in a display window, which includes therein various command functions for
invoking drawing tools. These command functions may take the form of
menu items in a menu 22 associated with the workspace 20, or may take the
form of toolbar items on a toolbar 24 associated with the workspace 20. It
will
be appreciated that the commands available on menu 22 and/or toolbar 24 may
be configurable by the user as appropriate for a particular application of the
invention.
Fig. 2 illustrates the invocation of a drawing tool by the selction
with a cursor 26 (controlled by mouse 16) of an item on menu bar 22, causing
a pop-up menu 28 of commands to appear on workspace 20. By selection of a
command on menu 28, a specific command may be executed.
In the illustration of Fig. 2, the executed command is to add a
segment 30 to the drawing 21 being built in the workspace. This command
requires the definition of the dimensions of the new segment 30, and for this
purpose the execution of the command creates a dimensional input window 32
which appears in the workspace such as shown in Fig. 2.
Details of the dimensional input window 32 may be seen in Fig.
3. There, it can be seen that window 32 includes virtual buttons for input of
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numeric information by the movement and clicking of the cursor 26 (which is
modified to the appearance of a hand when over window 32). Also included
in window 32 is a text box 40 where the user may enter text for the dimension
requested by the drawing tool. As illustrated, the text entered in box 50 may
a
dimension as an arithmetic sum, difference, product or dividend of a number
of dimensions, each of which may be defined in separate units. A
dimensionless number appearing in text box 40 will be assumed to have a
default unit, which may be selected by the user. However, numbers that are
associated with a unit identifier, will be interpreted as having the
identified
unit, and will be converted to the default unit before the drawing tool
performs
the requested arithmetic operations.
Thus, in the example of Fig. 3, a dimension is defined as 30
feet six inches, plus 15 meters, minus 114 centimeters plus 3 yards. The
drawing tool will convert this sum to a dimension in the default unit (e.g.,
meters), and then use the resulting dimension to define the new element 30
being created in the workspace.
As seen in Fig. 3, window 32 includes virtual buttons for
creating dimension symbols. These include button 41 for meters (m), 42 for
centimeters (cm), 43 for millimeters (mm), 44 for yards (yd), 45 for feet ('
or
ft) and 46 for inches (in or "). Virtual buttons 41-46 simplify the process
for
inputting dimensions, particularly if the user has difficulty remembering the
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symbol for a dimension or does not wish to use the keyboard to type the
dimensional symbol into text box 40.
The parser that generates the display in Fig. 3 enables a
designer to enter metric and English measurements as they are read from a
plan, and perform basic arithmetic operations (addition, subtraction,
multiplication, division) to draw structural drawings without the need of a
unit
converter. The parser accepts industry standard unit symbols and annotations,
including ft and' for feet, in and " for inches, m for meters, cm for
centimeters,
yd for yards.
Referring now to Fig. 4, the process by which dimensions of
different units are parsed and converted, may be explained. In a first step
50,
the user invokes a drawing tool that requires the input of a dimension.
Thereafter, in step 52, the parser text box 40 is displayed in window 32 (Fig.
3), along with the virtual keypad, and the user then enters an input string.
The first item in the input string should be a number, extracted
at step 54 and enqueued at 56 (if a number is not the first item in the
string, an
error is returned 58. Then the next item in the input string is parsed at step
60.
If the next item is a unit designator (step 62), then the enqueued
number is converted from the identified unit to the standard or default unit
selected by the user, and processing returns to step 60 to parse the next
item.
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If the next item is an operator (step 66), the operator
is enqueued in step 68, and processing returns to step 60 to parse the next
item.
If the next item is a number (step 70), then the number is
enqueued and processing returns to step 60 to parse the next item.
Finally, if there are no further items (step 74), then processing
proceeds to step 76, and the queued numbers (which have been converted to
the standard unit), and the operators (if any) are evaluated to produce a
result,
which is the desired dimension for the invoked drawing tool.
Referring now to Fig. 5, data stored by the CAD system of the
present invention can be explained. It will be appreciated that the data shown
in Fig. 5 may all be embedded in a single file for a drawing, or may be stored
in multiple files of a suite of files relating to a particular drawing, both
implementations being within the scope contemplated by the present
invention.
As seen in Fig. 5, drawings are stored by the CAD system in a
drawing file 82, using a drawing format, such as the Open DWG format
promulgated by The DWG Alliance, now known as the Open Design Alliance,
(www.opendesi n.g com). Open DWG is an "open" drawing file format, based
on the DWG format licensed and popularized by Autodesk and its AutoCAD
software. The DWG Alliance offers utilities at the above noted website, to
convert Autodesk proprietary format files to OpenDWG and/or vice-versa.
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Additional data stored by the CAD system includes paper size /
paper orientation data 84 for a drawing file. The CAD system according to the
present invention does not store detailed printer information associated with
a
drawing file. Rather, when a user creates a layout to be printed, only the
size
of the paper and its orientation (Landscape/Portrait) is stored. This data may
be stored separately or embedded in the drawing file, as represented in Fig.
5.
The printer / plotter interface, described below, allows users to designate
printers according to the sizes they print, thus removing allowing detailed
printer information to be referenced separately from a drawing file.
To assign a printer to a specific paper size and orientation, the
CAD system utilizes a Drag & Drop Interface. When a page is loaded for
printing, the CAD system loads the installed printer/plotters into a listbox
control. The user may then drag and drop printers (via mouse down events)
from the list of printers to specific text box control associated with
standard
paper sizes, e.g., A/Letter/8.5x11, B/Ledger/Tabloid/11x17,
Architectural/D/Poster/24x36, E/Poster/36x48. The system usefully focuses
on standard paper sizes and types, streamlining printing, as compared to other
CAD programs which attempt to support more paper sizes but by so doing
introduces complexity that is normally unnecessary.
Thus, were a user to create a drawing file with 15 layout pages
to be printed on D size paper, and 14 pages for Letter size and then print
those
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pages, the CAD system would automatically identify the printer or plotter on
which to print those pages, based upon the page sizes, without any
modification to the files required. It is believed that existing drafting
software
lacks any similar function, and typically will require changes to
printer/plotter
settings within files to adapt those files to particular printers, before they
can
be printed.
Fig. 5 further illustrates an undo file 86 utilized by the CAD
system. The CAD system of the present invention provides what is believed to
be a novel function for editing drawing files. Specifically, the inventive
approach provides lifelong access to each command executed by a user in
creating a drawing, via the "Undo" function. Unlike other known drawing (and
word processing applications), the CAD system of the present invention
maintains undo information permanently, even when files are saved and
retrieved, unless the user explicitly deletes undo information. Undo
information is also accessible when a file created by a first user is
transferred
to a second user.
As shown in Fig. 5, each command that may be undone is saved
in nonvolatile storage, such as on the hard drive of the CAD system. Each
time user executes a command, the system automatically generates an entry in
the undo file 86, identifying the state of the drawing file and the executed
command, in the following format:
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(6); 9,28,05; 11;34;25am; Add Wal1.FCD
In this format, the first field (6) indicates that this command is the 6th
command executed by the user, 9,28,05 indicates the exact date the command
was executed, 11;34;25am indicates the exact time that this command is
executed, and Add Wall FCD indicates the command executed by the user.
Fig. 5 illustrates an Undo file 86 having multiple records of
commands that were sequentially invoked in the creation of the illustrated
drawing file.
It will be noted that at any time, the current state of a drawing is
associated with a specific current entry 88 in the commands stored in the undo
file 86. The current entry 88 is frequently the last entry in the undo file
86, but
need not be; if the user undoes a command, the current entry 88 is moved to
entries prior to the last entry, corresponding to the drawing state seen by
the
user. If the user subsequently redoes undone commands with a "Redo" tool,
the current entry 88 is moved toward the last entry, again corresponding to
the
drawing state seen by the user.
The Undo storage approach described here, and its advantages,
are believed applicable to any software, not limited to CAD software. For
example, word processing applications such as Word, WordPerfect and
AmiPro, spreadsheet applications such as Excel, Quattro Pro or 1-2-3,
presentation applications such as Powerpoint, and other applications may take
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advantage of an Undo function as described. In all such applications, due to
carelessness or time pressure, it is likely that a user may not save work
done,
in which case an application crash or a power loss may lead to loss of the
entire file. Even if the user has saved periodically, or has used an automatic
function of the application to save periodically, not all of the changes made
will be preserved. In comparison, the technique described herein avoids the
loss of any part of a project because each change is saved as it is made. The
CAD system of the present invention thus protects the invested time of the
user, providing unlimited undo capabilities even after closing and opening a
10. file.
Referring now to Fig. 6, the use of the information shown in
Fig. 5 may be elaborated. In a first step 90 in Fig. 6, the user invokes a
function of the user interface. Specifically, the user may invoke 92 a drawing
tool, in response to which a new entry in the undo file is created. Notably,
if
the current entry is not the last entry in the undo file, subsequent entries
must
be deleted. Thus, in a first step 93, any stored conunands in entries
subsequent
to the current entry in the undo file are deleted. Then, in step 94, the date,
time, and drawing tool command and its parameters are stored in a new entry
the undo file 86.
After having used a drawing tool, the user may invoke 96 the
undo tool, in which case the system undoes (step 98) the command identified
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in the current entry of the undo file. Note, however, that the undone command
is not deleted, but is maintained in the undo file. Instead, in step 106, the
previous command in the undo file is made current, thus maintaining the
undone comrnand for a possible later "redo" of that command.
If the user invokes 102 the redo tool, in step 104 the system
redoes the last undone command, by executing the command identified in the
next entry in the undo. Also, the next entry in the undo file is made the
current
entry, so that the current entry corresponds to the state of the content
displayed
to the user.
Referring now to Fig. 7, the process for printing from the user
interface 90 can be elaborated. As noted above, if the user invokes 108 a
print
command, the CAD system selects (step 110) a printer based upon the
identified paper size and orientation of each page of the current drawing, and
in step 112, prints each page to the pre-defmed printer for that paper size
and/or orientation.
While the present invention has been illustrated by a
description of various embodiments and while these embodiments have been
described in considerable detail, it is not the intention of the applicants to
restrict or in any way limit the scope of the appended claims to'such detail.
Additional advantages and modifications will readily appear to those skilled
in
the art. The invention in its broader aspects is therefore not limited to the
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specific details, representative apparatus and method, and illustrative
example
shown and described. Accordingly, departures may be made from such details
without departing from the spirit or scope of applicant's general inventive
concept.
What is claimed is:
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